The present invention relates to apparatus for cutting sheet-like material, and more particularly, to apparatus for shearing workpieces of different sizes and shapes having at least two walls formed of sheet-like material, such as metal framing studs and eavestroughs.
Metal framing studs are used in the building industry, and particularly the commercial building industry, for constructing framework and mounting thereto wallboards formed of sheet rock and other types of materials. Although framing studs may be formed in a variety of different shapes and configurations, a common type of stud is formed of metal, and defines a back wall and two parallel side walls forming a generally U-shaped cross section. Conmmercially available studs are supplied in standard lengths, and therefore if a non-standard length is required, a standard stud must be trimmed, frequently by the builder, to the desired length.
Stud trimming is often performed at job sites by employing a chop saw having an abrasive wheel, disk or like rotatably-driven blade, which is pivotally mounted on a base for movement into and out of engagement with a workpiece. The chop saw blades can wear relatively quickly, particularly when used to cut heavy-gauge workpieces. In addition, because of limitations in blade size, many chop saws cannot cut through relatively large-width studs with a single cutting stroke, but rather require the stud to be flipped over after cutting through one side, and then cut again in order to cut through its entire width. Use of a chop saw to trim framing studs or like workpieces can therefore be a relatively time-consuming, labor-intensive and expensive operation, particularly at large job sites or jobs otherwise requiring a large number of studs or like workpieces to be trimmed.
Manufacturers of framing studs, eavestroughs or like workpieces have employed machines for shearing such workpieces to their desired lengths at the time of manufacture. A typical such machine employs a guillotine-like cutting blade slidably received within a blade gap, and a pair of die plates mounted on opposite sides of the guillotine relative to each other for slidably receiving and supporting the workpiece during a cutting operation. Each die plate defines an aperture which is shaped to conform to the shape of a respective type and size of workpiece for conformably engaging the workpiece. A typical such apparatus is shown in U.S. Pat No. 4,218,946 to Witzler, entitled xe2x80x9cCutter Assembly For Eavestrough-Forming Machinexe2x80x9d.
One of the drawbacks of these types of conventional shearing machines is that they cannot be conveniently employed for cutting a variety of different pre-manufactured studs, eavestroughs or like workpieces. Each die plate typically forms an aperture defining a fixed shape and dimension conforming to a manufacturer""s particular type and size of workpiece, and therefore can only be used with the respective type of workpiece. In addition, framing studs and like workpieces frequently become bent or otherwise slightly deformed during transportation, thus preventing such workpieces from being received within their corresponding die plates. Accordingly, although such a machine could be used to cut a variety of framing studs or like workpieces by providing a variety of die plates having apertures of different shapes and configurations, this would not only be relatively expensive, but any slightly deformed workpieces could not be received within the die plates, and thus could not be cut by the machine.
Accordingly, it is an object of the present invention to overcome the drawbacks and disadvantages of the above-described machinery for cutting metal studs, eavestroughs or like multi-walled workpieces.
The present invention is directed to an apparatus for shearing workpieces having at least two sides formed of sheet-like material. The apparatus comprises first means defining an elongated edge that is engageable with a first side of the workpiece for contacting and supporting the first side of the workpiece along a line defined by the edge. The apparatus further comprises second means defining an elongated edge that is engageable with a second side of the workpiece for contacting and supporting the second side of the workpiece. The second means is spaced apart from and faces the first means and defines a channel therebetween for receiving the workpiece. Each of the first and second means is independently movable relative to the other for engaging with each elongated edge the respective sides of workpieces of different widths. A shearing means of the apparatus is slidably received within a gap formed adjacent to the elongated edges of the first and second means, and is movable between a first position spaced away from the workpiece within the channel and a second position in engagement with the workpiece for shearing the workpiece along a line of contact. At least one of the first and second means is selectively positionable relative to the other for orienting an axis of the workpiece at a predetermined angle relative to a plane of the shearing means and shearing the workpiece at a predetermined angle relative to its axis.
In a preferred embodiment of the present invention, the first and second means for contacting and supporting the workpiece comprises first and second pairs of supports. A base support may be provided which defines a support surface extending between the elongated edges and which is engageable with a third side of the workpiece. A pair of base members may be slidably disposed on the base support, and the first and second pairs of supports may each comprise a pair of upstanding members wherein at least one of which is slidably disposed on the base members. A pair of shims each may be disposed between a respective pair of upstanding members and the base members to thereby define a dimension of the gap. The shearing means may comprise a blade having a cutting edge comprising at least three cutting tips. Optionally, the cutting edge may comprise at least four substantially planar surfaces wherein each of the planar surfaces are separated one from another by one cutting tip.
One advantage of the apparatus of the present invention, is that it is adaptable to rapidly and effectively shear a variety of workpieces, such as framing studs, having different sizes, shapes and/or configurations. For example, in one particular embodiment of the invention, each pair of upstanding members is connected together and, therefore, is movable as a unit for ease in accepting various workpieces for cutting thereof.
Other objects and advantages of the present invention will become apparent in view of the following detailed description and accompanying drawings.